The three furlough days effectively reduce pay by about 14 percent for most of the state's more than 200,000 workers. The furloughs also shut down most of state government three Fridays each month.

SEIU had negotiated a contract with the administration in February that would have limited its 95,000 members to a single monthly furlough day. Republican legislators blocked the contract's ratification, and Schwarzenegger said he had no choice but to add furlough days to help the state close a $26 billion budget deficit.

The three monthly furloughs will continue through June 2010 under the budget revision Schwarzenegger signed into law on Tuesday.

"This is about our contract," SEIU President Yvonne Walker said in a statement announcing the vote. "Whether it is through litigation, negotiations or any other actions that are necessary, we're in this for the long-haul to right this wrong to our members. We negotiated in good faith, we have offered cost-saving solutions, and we need our contract to be ratified."

She said the contract negotiated with the administration would have saved the state $340 million, and blamed the Republican governor for the plan's failure in the Legislature.

"Instead of showing leadership, he has tried to use state workers as pawns in his political games," she said. "Our members have sent a message that we are not going to stand by and let him hurt California, our families and ruin the quality public services we provide."

The union represents state employees including clerks, auditors, teachers, librarians, custodians and nurses.